[Qemu-devel] [PATCH 00/15] s390: vfio-ccw dasd ipl support

[Jason J. Herne]

This is to support booting from vfio-ccw dasd devices. We basically implement
the real hardware ipl procedure. This allows for booting Linux guests on
vfio-ccw devices.

vfio-ccw's channel program prefetch algorithm complicates ipl because most ipl
channel programs dynamically modify themselves. Details on the ipl process and
how we worked around this issue can be found in docs/devel/s390-dasd-ipl.txt.

NOTE: It has been a while, but I've finally chased down my infamous "reset bug".
On subsystem reset (I see this right after host ipl) we sometimes end up getting
an unexpected unit check status from a dasd device. This causes the first start
subchannel instruction to fail due to the pending unit check status. My solution
to this problem, as advised by the kernel folks, is to simply retry my ssch
instructions before declaring failure when unexpected unit checks happen. In the
event of a persistent error, after two retries we'll give up and print some
useful error info for the user.

Changelog
==========

rfc -> v1
---------
- Retry start subchannel operations on unexpected unit check status
- Print more complete state information on i/o error
- Fixed asm constraints (Q -> QS)
- Align lowcore to 8k boundary
- Initialize next_cpa in run_dynamic_ccw_program to avoid compiler warning
- Cleanup: Rework handling of i/o interrupts in assembler
- Fix netboot image (include cio.o in make file)
- Misc cleanups

Jason J. Herne (15):
  s390 vfio-ccw: Add bootindex property and IPLB data
  s390-bios: decouple cio setup from virtio
  s390-bios: decouple common boot logic from virtio
  s390-bios: Extend find_dev() for non-virtio devices
  s390-bios: Factor finding boot device out of virtio code path
  s390-bios: Clean up cio.h
  s390-bios: Decouple channel i/o logic from virtio
  s390-bios: Map low core memory
  s390-bios: ptr2u32 and u32toptr
  s390-bios: Support for running format-0/1 channel programs
  s390-bios: cio error handling
  s390-bios: Refactor virtio to run channel programs via cio
  s390-bios: Use control unit type to determine boot method
  s390-bios: Add channel command codes/structs needed for dasd-ipl
  s390-bios: Support booting from real dasd device

 docs/devel/s390-dasd-ipl.txt     | 132 ++++++++++++++
 hw/s390x/ipl.c                   |  15 ++
 hw/s390x/s390-ccw.c              |   9 +
 hw/vfio/ccw.c                    |  13 +-
 include/hw/s390x/s390-ccw.h      |   1 +
 include/hw/s390x/vfio-ccw.h      |  38 ++++
 pc-bios/s390-ccw/Makefile        |   2 +-
 pc-bios/s390-ccw/cio.c           | 374 +++++++++++++++++++++++++++++++++++++++
 pc-bios/s390-ccw/cio.h           | 236 +++++++++++++++++++-----
 pc-bios/s390-ccw/dasd-ipl.c      | 249 ++++++++++++++++++++++++++
 pc-bios/s390-ccw/dasd-ipl.h      |  16 ++
 pc-bios/s390-ccw/libc.h          |  23 +++
 pc-bios/s390-ccw/main.c          | 161 +++++++++++------
 pc-bios/s390-ccw/netboot.mak     |   2 +-
 pc-bios/s390-ccw/netmain.c       |   1 +
 pc-bios/s390-ccw/s390-arch.h     | 113 ++++++++++++
 pc-bios/s390-ccw/s390-ccw.h      |  10 +-
 pc-bios/s390-ccw/start.S         |  33 +++-
 pc-bios/s390-ccw/virtio-blkdev.c |   1 +
 pc-bios/s390-ccw/virtio.c        |  46 +----
 roms/SLOF                        |   2 +-
 tests/boot-serial-test.c         |   2 +-
 22 files changed, 1308 insertions(+), 171 deletions(-)
 create mode 100644 docs/devel/s390-dasd-ipl.txt
 create mode 100644 include/hw/s390x/vfio-ccw.h
 create mode 100644 pc-bios/s390-ccw/cio.c
 create mode 100644 pc-bios/s390-ccw/dasd-ipl.c
 create mode 100644 pc-bios/s390-ccw/dasd-ipl.h
 create mode 100644 pc-bios/s390-ccw/s390-arch.h

--
2.7.4